EVM (Ethereum Virtual Machine)

The EVM is a virtual computer defined by the Ethereum protocol. Smart contracts written in languages such as Solidity are compiled into bytecode, a list of simple instructions called opcodes, and every node runs that bytecode to process transactions and update the shared state. Each opcode has a gas cost, which limits how much computation a transaction can use and prevents endless loops.

Because developers, tools and wallets already work with it, the EVM has become an industry standard. Many networks, including BNB Chain, Avalanche's C-Chain, Polygon and most layer 2 rollups, are EVM-compatible, so the same contracts and addresses work across them. Competing designs include the Solana Virtual Machine and Move-based chains such as Sui and Aptos.

EVM compatibility makes it easy to copy code between chains, bugs included, so a flaw found in one fork often affects others. Contracts are generally immutable once deployed, and the EVM processes transactions one after another, which limits throughput.